Farm buildings and industrial storage buildings are generally provided with track hung sliding doors that are movable across the face of the wall of the buildlng to block a door opening provided in the wall. The door openings may either have a single sliding door or double sliding doors in order to close the opening. The support structure for the doors generally included a circular or box type track member having mounting brackets with integral track cover support extensions secured to the top of the track member. Since the track cover extensions were permanently mounted on the support structure, the user was limited to a track cover that corresponded to the extensions.